title: Highly sensitive method for the determination of omeprazole in human plasma by liquid chromatography-electrospray ionization tandem mass spectrometry: application to a clinical pharmacokinetic study.
abstract: A highly sensitive, rapid assay method has been developed and validated for the estimation of omeprazole (OPZ) in human plasma with liquid chromatography coupled to tandem mass spectrometry with electrospray ionization in the positive-ion mode. The assay procedure involves alkalinization of plasma followed by simple liquid-liquid extraction of OPZ and lansoprazole (internal standard, IS) from human plasma with acetonitrile. Chromatographic separation was achieved with 0.01 M ammonium acetate:acetonitrile (40:60, v/v) at a flow rate of 0.25 mL/min on an Inertsil ODS 3 column with a total run time 2.5 min. The MS/MS ion transitions monitored were 346.1 --> 198.1 for OPZ and 370.1 --> 252.1 for IS. Method validation and clinical sample analysis were performed as per FDA guidelines and the results met the acceptance criteria. The lower limit of quantitation achieved was 0.05 ng/mL and the linearity was observed from 0.05 to 10.0 ng/mL. The intra-day and inter-day precisions were in the ranges 2.09-8.56 and 5.29-8.19%, respectively. This novel method has been applied to a pharmacokinetic study of OPZ in humans.
authors.affiliation: Drug Metabolism and Pharmacokinetics, Discovery Research, Dr Reddy's Laboratories Ltd, Miyapur, Hyderabad-500049, India.
authors.forename: Shivva
authors.initials: S
authors.lastname: Vittal
authors.forename: Ramesh
authors.initials: R
authors.lastname: Ganneboina
authors.forename: Buddhadev
authors.initials: B
authors.lastname: Layek
authors.forename: Ravi Kumar
authors.initials: RK
authors.lastname: Trivedi
authors.forename: Kishore Kumar
authors.initials: KK
authors.lastname: Hotha
authors.forename: D Vijaya
authors.initials: DV
authors.lastname: Bharathi
authors.forename: Ramesh
authors.initials: R
authors.lastname: Mullangi
mesh_terms: D053000:Analytic Sample Preparation Methods; D000897:Anti-Ulcer Agents / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004791:Enzyme Inhibitors / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D006801:Humans; D009853:Omeprazole / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000897:Anti-Ulcer Agents; D004791:Enzyme Inhibitors; D009853:Omeprazole